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<div class="titlepage"><div><div><h4 class="title">
<a name="boost_asio.reference.async_connect.overload1"></a><a class="link" href="overload1.html" title="async_connect (1 of 6 overloads)">async_connect
        (1 of 6 overloads)</a>
</h4></div></div></div>
<p>
          Asynchronously establishes a socket connection by trying each endpoint
          in a sequence.
        </p>
<pre class="programlisting">template&lt;
    typename <a class="link" href="../Protocol.html" title="Protocol requirements">Protocol</a>,
    typename <a class="link" href="../Executor1.html" title="Executor requirements">Executor</a>,
    typename <a class="link" href="../EndpointSequence.html" title="Endpoint sequence requirements">EndpointSequence</a>,
    typename <a class="link" href="../RangeConnectHandler.html" title="Range connect handler requirements">RangeConnectHandler</a> = <a class="link" href="../asynchronous_operations.html#boost_asio.reference.asynchronous_operations.default_completion_tokens"><span class="emphasis"><em>DEFAULT</em></span></a>&gt;
<a class="link" href="../asynchronous_operations.html#boost_asio.reference.asynchronous_operations.automatic_deduction_of_initiating_function_return_type"><span class="emphasis"><em>DEDUCED</em></span></a> async_connect(
    basic_socket&lt; Protocol, Executor &gt; &amp; s,
    const EndpointSequence &amp; endpoints,
    RangeConnectHandler &amp;&amp; handler = <a class="link" href="../asynchronous_operations.html#boost_asio.reference.asynchronous_operations.default_completion_tokens"><span class="emphasis"><em>DEFAULT</em></span></a>,
    typename constraint&lt; is_endpoint_sequence&lt; EndpointSequence &gt;::value &gt;::type  = 0);
</pre>
<p>
          This function attempts to connect a socket to one of a sequence of endpoints.
          It does this by repeated calls to the socket's <code class="computeroutput">async_connect</code>
          member function, once for each endpoint in the sequence, until a connection
          is successfully established.
        </p>
<h6>
<a name="boost_asio.reference.async_connect.overload1.h0"></a>
          <span class="phrase"><a name="boost_asio.reference.async_connect.overload1.parameters"></a></span><a class="link" href="overload1.html#boost_asio.reference.async_connect.overload1.parameters">Parameters</a>
        </h6>
<div class="variablelist">
<p class="title"><b></b></p>
<dl class="variablelist">
<dt><span class="term">s</span></dt>
<dd><p>
                The socket to be connected. If the socket is already open, it will
                be closed.
              </p></dd>
<dt><span class="term">endpoints</span></dt>
<dd><p>
                A sequence of endpoints.
              </p></dd>
<dt><span class="term">handler</span></dt>
<dd>
<p>
                The handler to be called when the connect operation completes. Copies
                will be made of the handler as required. The function signature of
                the handler must be:
</p>
<pre class="programlisting">void handler(
  // Result of operation. if the sequence is empty, set to
  // boost::asio::error::not_found. Otherwise, contains the
  // error from the last connection attempt.
  const boost::system::error_code&amp; error,

  // On success, the successfully connected endpoint.
  // Otherwise, a default-constructed endpoint.
  const typename Protocol::endpoint&amp; endpoint
);
</pre>
<p>
                Regardless of whether the asynchronous operation completes immediately
                or not, the handler will not be invoked from within this function.
                On immediate completion, invocation of the handler will be performed
                in a manner equivalent to using <a class="link" href="../post.html" title="post"><code class="computeroutput">post</code></a>.
              </p>
</dd>
</dl>
</div>
<h6>
<a name="boost_asio.reference.async_connect.overload1.h1"></a>
          <span class="phrase"><a name="boost_asio.reference.async_connect.overload1.example"></a></span><a class="link" href="overload1.html#boost_asio.reference.async_connect.overload1.example">Example</a>
        </h6>
<pre class="programlisting">tcp::resolver r(my_context);
tcp::resolver::query q("host", "service");
tcp::socket s(my_context);

// ...

r.async_resolve(q, resolve_handler);

// ...

void resolve_handler(
    const boost::system::error_code&amp; ec,
    tcp::resolver::results_type results)
{
  if (!ec)
  {
    boost::asio::async_connect(s, results, connect_handler);
  }
}

// ...

void connect_handler(
    const boost::system::error_code&amp; ec,
    const tcp::endpoint&amp; endpoint)
{
  // ...
}
</pre>
<h6>
<a name="boost_asio.reference.async_connect.overload1.h2"></a>
          <span class="phrase"><a name="boost_asio.reference.async_connect.overload1.per_operation_cancellation"></a></span><a class="link" href="overload1.html#boost_asio.reference.async_connect.overload1.per_operation_cancellation">Per-Operation
          Cancellation</a>
        </h6>
<p>
          This asynchronous operation supports cancellation for the following <a class="link" href="../cancellation_type.html" title="cancellation_type"><code class="computeroutput">cancellation_type</code></a>
          values:
        </p>
<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; ">
<li class="listitem">
              <code class="computeroutput">cancellation_type::terminal</code>
            </li>
<li class="listitem">
              <code class="computeroutput">cancellation_type::partial</code>
            </li>
</ul></div>
<p>
          if they are also supported by the socket's <code class="computeroutput">async_connect</code> operation.
        </p>
</div>
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<td align="right"><div class="copyright-footer">Copyright © 2003-2021 Christopher
      M. Kohlhoff<p>
        Distributed under the Boost Software License, Version 1.0. (See accompanying
        file LICENSE_1_0.txt or copy at <a href="http://www.boost.org/LICENSE_1_0.txt" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>)
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